Shrink sleeve labels are widely used for decorating containers. Shrink sleeve labels provide several advantages over other labeling and decoration techniques including the ability to decorate the entire peripheral wall of irregularly shaped packages, the ability to generate a variety of visually distinct packages using a single container shape, and the ability make rapid changes to artwork for packages.
For some packages, designers desire to have an opening in the shrink sleeve to provide a window through which the underlying container and or contents of the container are visible or to provide a location to grip the package. Openings can be provided in shrink sleeves by including a pre-cut hole in the shrink sleeve prior to the shrink sleeve being placed over the container and subsequently shrunk. A problem with this approach is that there are technical difficulties with precisely registering the shrink sleeve with the container so that the pre-cut hole, when shrunk, is located as desired, particularly for high speed packaging lines. Further, as the shrink sleeve is shrunk, the hole can tend to become uncontrollably irregularly shaped as tension develops in the shrink sleeve. For containers having a grip, such as an indention, pair of indentions, or through handle, a pre-cut hole in a shrink sleeve that is poorly registered with such feature can result in a grip that has decreased functionality. The decrease in functionality can arise as a result of portions of the shrink sleeve adjacent the cut-out covering portions of the container that the package designer desires the consumer to be able to contact directly. Such an arrangement can result in the consumer having to form part of her grip on the package over an unexpectedly slick shrink sleeve, which can cause the package to slip from her grasp in use. The decrease in functionality can also arise as a result of an edge of the pre-cut hole ending up in a location at which the shrink sleeve is not able to maintain contact with the container after the shrink sleeve is shrunk. Such an arrangement can impede the consumer's ability to securely grasp the grip.
A hole can be created in a shrink sleeve after the shrink sleeve is shrunk onto the container. For a container having a grip, a hole can be punched in the shrink sleeve. Punching a hole in a shrink sleeve after the shrink sleeve has been shrunk onto the container can result in irregular holes being formed. That is, the resulting holes can have an irregular and uncontrolled shape in and of the hole itself and there can be irregularity amongst holes created across multiple packages formed on a single manufacturing line.
With these limitations in mind, there is a continuing unaddressed need for a process and apparatus for forming holes in shrink sleeve labels.